(1) Field of the Invention
The present invention relates to a transmission joint body having a composite structure. The transmission joint is a homokinetic joint having a joint body portion that includes an envelope with bearing paths defined inside the envelope, the bearing paths receiving articulation elements of the joint.
(2) State of the Prior Art
A transmission joint body described and illustrated in U.S. patent application Ser. No. EP-A-0 335,781, corresponding to U.S. Pat. No. 5,009,628, comprises several bearing paths arranged around the axis of a joint body working in conjunction with jointing elements of the transmission joint. A connection system connects the joint body to a transmission device. The joint body further has a casing inside which the bearing paths are arranged. The bearing paths are defined by a plurality of bearing tracks disposed inside the casing. Between the peripheral surface of the casing and the rear surfaces of the bearing tracks is defined an interior space that is filled with a material made of one of a thermosetting and a thermoplastic matrix.
In the various embodiments described and illustrated in the above-referenced document, the casing exists as a cylindrical or axisymmetric part having a substantially constant thickness. Each of the bearing paths, as noted above, is defined by tracks formed by one or a plurality of inserts, whose facing surfaces operate in pairs in conjunction with the jointing elements of the transmission joint.
The design of the above-discussed transmission joint makes it possible, while preserving or increasing the torque-transmission capabilities, to substantially reduce the weight of the joint as well as to improve the vehicle comfort level, while more effectively filtering out noise and vibrations generated in the transmission joint. The joint further provides a very high corrosion resistance.
However, it can be observed that the filling material, whether or not the filling material is reinforced with short fibers or particles, and which material provides for the transmission of torque between the bearing tracks and the connection system, is present in large amounts, and thus does not function under ideal conditions, in particular given the significant specific loads that are variable in magnitude to which the joint is subjected.